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A Pollster Grinch Effect?

Topics: 2008 , Likely Voters , The 2008 Race

While pondering some new poll results from Iowa last night, MyDD's Jon Singer asked some good questions:

How do you come up with a turnout model when you don't know what day the caucuses are going to be held? Specifically, does anyone actually believe that turnout for a Thursday night January 3 caucus, when many voters just won't have the time to take two hours to participate, would be the same as the turnout on a Saturday afternoon January 5 caucus, when significantly fewer voters will be working or have just gotten off of work? Might not the turnout also be different were the Democratic caucuses to be held on Tuesday night January 14, which Ben Smith says is a possibility?

It could be the case that the sentiments of voters 1 through 125,000 are not terribly different from those of voters 125,001 through 150,000 or 175,000 or 200,000. But then again, it also could be the case that those going to caucus for the first time ever or even the first time in many years are a whole lot different from those who are already pretty determined to keep up their streak of making it to the caucuses every four years.

So do we need to consider a "pollster Grinch Effect? Does uncertainty surrounding the date of the Iowa caucuses make it even more difficult for pollsters to identify and sample "likely caucus goers?" Yes and yes, but...

While Singer is asking all the right questions, he is probably giving pollsters too much credit for our ability to divine likely caucus goers with laser-like precision, regardless of our assumption about the level of turnout. A public opinion poll is basically a blunt instrument when it comes to "modeling" likely caucus participants. The primary measures that most public pollsters use to select likely caucus goers are self-reports of interest in the caucus, and intent to participate and (in a few cases) self-reports of past participation. Unfortunately, respondents notoriously overstate their intent to vote. Most want to show an interest in doing their civic duty, especially when asked by a stranger on the telephone. So rather than take responses at face value, most pollsters use several different questions in combination to try to narrow their "likely voter" subgroup to some reasonable number.

A few public polls in Iowa have sampled from lists of registered voter lists, a procedure that at least provides an accurate way to screen out non-registrants and sort out those registered as Democrats, Republicans or with no affiliation. But as ABC's Gary Langer points out, those lists only eliminate the roughly 17% of the adult population that is either not registered or identified as "inactive" voters by Iowa's Secretary of State. The record of actual party affiliation is helpful to pollsters but not a conclusive indicator of their caucus of choice, since Iowa voters can register or declare their party affiliation on caucus night.

Only one or two public Iowa polls have used actual vote history to select their respondents, and -- except for the recent polls conducted for the One Campaign -- none have used past caucus participation to select their likely caucus-goer samples.

So the bottom line is that even if we knew exactly how many voters planned to participate, modeling the likely caucus goers comes down to methodology decisions that amount to an educated guess, at best. And even then, we have very little idea how many Iowans will participate. Consider the estimated turnout from past years (from an offline source: Rhodes Cook's invaluable Race for the Presidency: Winning the 2004 Nomination):

10-18%20iowa%20turnout.png

Look closely at the contested Democratic races, 1980, 1984, 1988, 2000 and 2004. "Estimated" turnout varied enormously, from an estimated 60,000 to 124,000. And as we learned last week, some have expressed doubt about the 2004 estimate, since caucus organizers ran out of sign-in sheets and failed to record name and address information for nearly twenty thousand participants.

And finally, we have to consider that every campaign is doing everything it can to identify and, ultimately, turn out voters who are not typical caucus goers. Some are devoting literally millions of dollars to microtargeting, field staff and various forms of "voter contact" to alter the turnout in their favor.

So - before we contemplate the Grinch Effect - what level of turnout is likely in 2008? Who knows?

What this means for the polls we plot and obsess over is that they are, at best, blunt measures of voter preferences based in Iowa, and no two pollsters define "likely caucus goers" alike. They do give us a decent sense of trends - who is gaining or falling -- especially for surveys done by the same pollster using a constant methodology. However, the "point estimate" for any candidate on any one poll has a lot of room for error, the kind that has absolutely nothing to do with the statistical "margin of error."

 

Comments
Chris S.:

1984 and 2000 aren't really in the same league as 1988 and 2004 in terms of being "contested" they were. I was too young to be following politics in 1984, but in looking up the results, it appears that Mondale won by a huge margin, so, assuming he was heavily favored to win beforehand, voters might have had less reason to turn out. And in 2000, there were only two candidates, and Bradley was given little chance of winning in Iowa.

If the Iowa polls remain as close as they are now, I would expect that the turnout would end up being similar to 1988 or 2000, when you had multiple candidates who were competitive. Of course, that assumes there's no "Grinch" effect.

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